Not really. Eight hours for sleep covers almost everyone's biological requirements. It's hard to decide in what proportion to split the remaining 16. So split it 50-50 unless someone can propose something better!
That's a bafflingly unfounded and useless "suggestion!" Enormous amounts of people have been working 8 hour shifts for decades -- instead of just guessing that the status quo is probably optimal, why not ask a variety of people if they think two hours more of family/leisure/commute/exercise/learning time would be of any benefit?